Right whales are so-named because whalers considered them the 'right' whales to hunt - they were easy to approach and catch; floated when dead, and had a lot of oil in the cells of their blubber. North Pacific right whales came very close to extinction in the early 1900s and are the most endangered of the great whales (along with the North Atlantic right whale). Current population estimates are unknown but it is likely that only a few hundred animals remain. There is some evidence to support the idea of two separate stocks of North Pacific right whales; eastern and western North Pacific and therefore any population estimate of the 'species' may be misleading.

Appearance:

The North Pacific right whale is notable for its huge head (almost one third of the animal's total length) and strongly arched mouthline. The whale carries horny growths called callosities mostly on the upper jaw and head with the largest of these growths, found on the tip of the nose, called the 'bonnet'. The only species that is likely to be confused with them is the bowhead whale, which lacks the callosities. Whale lice live on these callosities and make them white, pink, yellow or orange. The right whale has two blowholes and when it exhales, produces a V-shaped spout up to 5m high. The right whale has a heavy, rotund body, black or dark grey, with white blotches on the belly. There is no dorsal fin and it has long, broad flippers which have small ridges running down them. These ridges trace the bones inside which are in a similar arrangement to human ‘finger bones'. Male right whales are also notable for having the largest testes in the world - each pair weighs about a tonne!

Behaviour:

Little is known about the behaviour of North Pacific right whales as there have been very few at-sea sightings of the animals in the past decades. Right whales swim slowly, yet are surprisingly acrobatic, they are known for breaching and slapping their flippers against the water when rolling over. They are playful, curious animals, and often poke and bump objects they find in the water. Their friendly nature means they may swim up to boats, and even let boats approach them. They have been known to raise their tail flukes out of the water and use them as sails. As far as we know this is a form of play.

Distribution:

Historically, North Pacific right whales lived across the entire North Pacific however commercial and illegal whaling operations decimated the species. Little is known of the current distribution but consistent sightings (between April and September) in the Bering Sea led to a portion of this area designated as Critical Habitat for the species in 2006. Records at other times of the year are few and far between, the location of a breeding ground is unknown and it is possible that unlike other right whales, they prefer to breed in offshore areas. North Pacific right whales are currently threatened by habitat loss, human disturbance, entanglement in fishing gear and collisions with vessels. The IUCN lists the species as Endangered (2008).